Water jet surgical devices are being increasingly used in surgery because their cutting or, better said, their separating behavior is different from the usual scalpels and alternative devices such as laser surgical or RF surgical apparatuses.
In particular, water jet surgical devices can be used for incisions that separate certain tissue types and leave others untouched (i.e., selective tissue separation).
Finally, such techniques are being increasingly used in endoscopic surgical procedures.
Such water jet surgical devices comprise a fluid reservoir and a fluid conveyor system for conveying the fluid through a pressure line from the fluid reservoir to a water jet surgical instrument that is connected to the water jet surgical device. The water jet surgical instrument itself comprises an ejection nozzle to eject the fluid in the form of a fine fluid jet.
In the resection of tissue, e.g., tumor tissue in the gastrointestinal tract, the water jet must leave the ejection nozzle bundled under high pressure. If—as in the aforementioned example application—the resection of the tumor tissue is limited to the mucosa, the tumor tissue should be ectomized as completely as possible and, if possible, in one session; this being possible with a fluid jet. In conjunction with this, however, there is a problem that the “bundled” fluid jet can result in a perforation of the muscularis propria. The consequence of such perforation is dangerous internal bleeding concealing the surgical site. Furthermore, considering other applications of water jet surgical devices, it is desirable to change the exit angle of the fluid jet such that inadvertent injuries caused by the surgeon do not occur or that other functions of the fluid jet are made possible (e.g., rinsing).
U.S. Pat. No. 5,944,686 discloses a surgical instrument for water jet surgery in which a cutting fluid jet is atomized via a deflecting surface and the exit angle of the fluid jet is changed. In doing so, this deflecting surface is arranged distally from the actual ejection nozzle.
German Publication DE 10 2007 002 486 A1 discloses a water jet surgical instrument in which a fluid jet having an essentially round cross-section impinges on a spoon-like impact surface and is converted there into a flattened water jet. In this case, the spoon-like surface is shaped as an elongated distal end of a suction pipe starting at this point, i.e., again, its location is distal to the ejection nozzle.
Consequently, until now, it has been unanimously suggested to provide special devices such as impact surfaces or deflecting surfaces to impart the fluid jet with a form deviating from the round cross-section or with another exit angle. However, such add-on devices interfere with the clear view of the surgical site and interfere with the work of the instrument itself because there is always another device downstream of the actual fluid dispensing element, the ejection nozzle, said device being in an unfavorable location for surgical work.